1. Field of the Invention
The invention relates to planetary cooler systems for rotary drums such as cement kilns.
2. Description of the Prior Art
In recent years rotary kilns have been designed for ever increasing outputs. The kilns are often constructed with a plurality of cooler tubes mounted in planetary fasion about their material outlet end. Owing to the increased output the planetary cooler tubes have had to be constructed in larger and larger units, with consequent increases in weight. The increase in weight subjects the kiln sections, at the points where the cooler tubes are attached, to very heavy mechanical loads.
Instead of using larger cooler tubes the number of tubes may be increased where large kiln plant diameters are involved, but the load to which the kiln sections are subjected is not altered appreciably. However, owing to the larger number of outlet openings in the kiln shell the risk of weakening the kiln sections always exists. If in order to obtain an improved cooling, more particularly of the inlet portions of the cooler tubes, the amount of cooling air is increased, this will cause an increasing amount of dust to be raised, with a consequent circulation of treated material between the kiln and cooler. I have invented a planetary cooler system for a rotary kiln which enables the kiln outlet to be increased while avoiding the risks of the prior art attempts.